Solutions of the HNC equations for lattice gas models of point defects in doped silver chloride

Autor: E. Loftus Allnatt, A. R. Allnatt
Rok vydání: 1982
Předmět:
Zdroj: The Journal of Chemical Physics. 76:3249-3259
ISSN: 1089-7690
0021-9606
DOI: 10.1063/1.443318
Popis: Solutions of the hypernetted chain equations have been obtained for temperatures from 50 to 450 °C for models of the Coulombic lattice gas of cation vacancies and impurity ions in AgCl doped with 0.5% to 5% of CdCl2. The method, based on coupled Newton–Raphson and Picard iterations, is outlined. Activity coefficients calculated from the results show substantial deviations from the Debye–Huckel values. At 350 °C, increasing with decreasing temperature, there is a concentration dependent enhancement of the like‐charge correlation function h++(r) to positive values at the second to fourth neighbor separations. This probably reflects the formation of defect clusters of more than two defects, but the effect may be exaggerated by deficiencies in the HNC approximation. The possibilities for similar HNC calculations on other lattice defect systems are discussed.
Databáze: OpenAIRE